Eddie Paolo Barillas spent 12 days camping out to buy these Nike Air Yeezy II’s for $245. Sneakerheads are now bidding as much as $5K for them on eBay.Zandy Mangold

Would you pay $90,000 for a pair of shoes? Earlier this month, some very rich fool did, reportedly plunking down the ridiculous sum on eBay for a pair of Nike Air Yeezy II’s, a hightop sneaker designed by Kanye West.

For that kind of mark-up on shoes retailing for $245, you should get Kanye himself to deliver them, scrub your feet, and perform for 900 of your closest friends. But that’s just how it goes in the world of limited-edition and collectible shoes, populated by rabid sneakerheads who will go to extravagant lengths — and prices — to nab the hottest new releases.

Eddie Paolo Barillas, 20, of Brooklyn has been collecting and reselling shoes for years, and his biggest sale, so far, is $5,000 for a pair of Air Jordan Undefeateds. He lives and breathes footwear and can rattle off tongue-twisting shoe names (Foamposite One “Galaxy,” anyone?), prices and release dates like a baseball announcer reciting stats.

“Ever since I was little, I always liked sneakers and fashion,” says Barillas, who resembles the similarly sneaker-obsessed Turtle from “Entourage.” “Getting the limited stuff, it’s fun for me.”

And when Barillas talks about sneakers, he’s not talking about the average pair you can pick up down at the local Payless. What he and his fellow sneakerheads are after are the extremely rare releases shoe companies, including Nike, Asics and New Balance, put out every few weeks for hard-core fanatics. In some cases, just a few hundred pairs are sold worldwide.

Here’s how the game works:

First, you have to find them.

This is not as easy as it sounds. Many times, companies announce a shoe’s release date, but they rarely if ever publicize which stores will be selling it. You can’t just ask at stores either, because they — in hopes of avoiding a melee at their registers — will often fib and say they won’t be getting any shipments.

The best bet is to know which stores have gotten which shoes in the past. A store that got, say, the Nike Air Yeezy I will probably get the sequel. “You have to talk to a lot of people to see what they know,” Barillas says. It also helps to have a connection inside Nike, as he does.

You have to sleep on a sidewalk.

Earlier this month, Barillas spent 12 days straight camping out for the Air Yeezy II’s. He ultimately landed two pairs at Jimmy Jazz in Brooklyn and says that if he decides to sell them he expects to get as much as $5,000.

“It’s not that bad. I like camping,” he says. “You really just sit down and chill.” He brings a beach chair to sleep on. Others bring sleeping bags and occasionally tents. The crowds waste time by playing Uno and dominos. To eat, they bring sandwiches from home or order pizza. Bathroom breaks mean begging local businesses to let them use theirs.

Barillas says over the past few years, more people have been getting into the game — including phonies he calls “hypebeasts” who are blindly following a trend — and now nabbing even a general-release pair like the latest Air Jordans means waiting in line for a few hours. As recently as 2009, he would be able to walk straight into the store and buy mass produced Jordans.

Figuring out exactly how early to get in line can also be tricky. It all depends on how limited a release is and how much heat surrounds it. Popular camping spots include Midtown’s Foot Locker, Harlem’s House of Hoops and the Upper West Side’s West NYC.

You have to figure out what size to buy.

If he’s buying the shoes to trade or resell (more on that later), Barillas often buys a larger size, like 11, because he’s figured out that people who wear basketball sneakers tend to have bigger feet. Unusual sizes, such as a really small 6 or a really large 13, can be risky to buy — though with potentially more reward. Because those sizes are rarer, competition for the pairs is much fiercer, though the pool of potential buyers is smaller.

Guard your purchases with your life.

Barillas says he’s seen some fights over shoes, but he’s personally never had any trouble making a clean escape from the store with his purchases. He quickly hops into a friend’s car or a cab, lest someone try to take his kicks.

For the love of all that’s holy, never actually put these shoes on your feet.

Really. Don’t even think about putting these on and, like, walking around. Barillas says he might consider wearing his Yeezy II’s for his wedding. Might.

The goal is to keep them in absolutely pristine condition. These are more like art objects than ordinary footwear.

“The longest I would ever wear them would be for like five or 10 minutes, and inside only and only on hardwood floors,” Barillas says. “Don’t wear them on the rug. It leaves a mark.”

Resell smartly.

Barillas is currently in search of a job and had to sell some shoes to make ends meet. “I get attached to them quickly, but if I have to sell them, I have to sell them,” he says. “It’s hurtful in a way.”

The best places to resell are on eBay, Craigslist and Facebook, which has lots of pages where sneakerheads can buy, sell and trade. And timing is everything. Those Air Yeezy II’s — auctioned for $90,000 before they were available in stores — are now going for about $5,000 on eBay.

Most of the wealthy buyers come from overseas, especially in Europe.

Knowing when to put them up for sale is also key. Barillas carefully watches the price before and just after the release to see if it might continue to go up or if it’s peaked.

He’s only lost money a couple of times: once on a pair of Blake Griffin Hyperdunks, another time on a pair of Kobe Bryant-branded Nikes.